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South Australian Election Simulation

Newspoll released 1500+ sample poll of South Australian voting intentions today in The Oz that you can take a squiz at over here. What this allows us to do is use that data to run one of our monte carlo election simulations on those figures to get a bit of a handle on the most […]

Newspoll released 1500+ sample poll of South Australian voting intentions today in The Oz that you can take a squiz at over here. What this allows us to do is use that data to run one of our monte carlo election simulations on those figures to get a bit of a handle on the most likely outcome of today’s result (assuming that the election result comes in within the MoE of the Newspoll figures) and attach some implied probabilities to possible outcomes.

The headline results of the simulation come in like this:

The most likely result is Labor winning 21 seats (where 24 is needed to govern outright), which would mean a total result of 21 ALP, 21 Liberal and 5 independents. You can’t get much more of a split parliament than that!

If we move across to the cumulative implied probabilities that measure the probability of the ALP winning at least X number of seats, this is what we get:

To read the chart, simply choose a number of seats at the bottom, go up to where the red line intersects and trace across to the left axis. That gives us the implied probability of the ALP winning at least that many seats today based on the Newspoll this morning. Tabling up the key numbers we get:

So the most likely outcome, based on the Newspoll, is a perfectly hung parliament with a 21/21/5 split between ALP/Liberal/Independents. However, nearly all the uncertainty in the numbers is actually on the upside for the ALP – meaning the second most likely result by far is 22/20/5 with the third and fourth being split 20/22/ 5 and 23/19/5

If the election result matches the polls, it more likely than not that the ALP will form a minority government – but those probabilities aren’t so great as to be a sure thing, just a likely thing.